PTA testing, the Westmead post traumatic amnesia scale and opiate analgesia: a cautionary note.

OBJECTIVE: To assess the validity of the Westmead PTA scale in patients treated with opiate analgesia. METHOD: Seventeen non-head injured, non-traumatic, electively hospitalized orthopaedic patients treated with opiate analgesia were tested on the Westmead PTA scale for a minimum of 2 consecutive days (n=17) to a maximum of 4 consecutive days (n=10). RESULTS: Only 20% of participants tested over 4 days reached criteria of three consecutive 12/12 scores on the Westmead PTA scale. Daily failure rates on the 12 item scale ranged from 36-70%. All failures were on the 'new learning' items, orientation items were never failed. CONCLUSIONS: The low pass rate of non-head injured patients treated with opiate analgesics indicates that the Westmead PTA scale is non-specific to traumatic brain injury and is probably an invalid measure of post-traumatic amnesia in patients actively treated with opiates. Implications for the measurement and accurate classification of traumatic brain injury patients are discussed.

Cognitive functioning after subthalamic nucleotomy for refractory Parkinson's disease.

OBJECTIVE: To evaluate whether subthalamic nucleotomy produces adverse cognitive effects in patients with Parkinson's disease. METHOD: Twelve patients with Parkinson's disease underwent stereotactic surgery to the subthalamic nucleus. Presurgical and postsurgical neuropsychological assessment of attention, memory, executive function, language, and verbal intellect were undertaken with a battery of tests designed to minimise potential contamination of cognitive effects by motor symptoms. RESULTS: There was no statistically significant difference in the cognitive tests results after operation for the group as a whole. Reliable change indexes were generated for the cognitive tests. Reliable change postoperatively was found on specific tests of verbal memory, attention, and planning. Left sided operations were associated with greater incidence of deterioration postsurgery. CONCLUSIONS: Preliminary data on the first reported cognitive changes after subthalamic nucleotomy suggested few adverse cognitive effects of the surgery although discrete neuropsychological changes were seen in some patients. These effects were consistent with current theories on the cognitive functions of the basal ganglia.

An analysis of neuropsychological change scores following selective temporal resection of the non-dominant temporal lobe.

Reliable change in neuropsychological test scores was examined in patients undergoing right-sided, selective temporal resections for the relief of intractable epilepsy. Measures were taken prior to surgery, 1-month post-operatively and 1-year post-operatively. Non-verbal memory performance was more robustly measured than in previous studies. Results failed to replicate previous studies which report verbal memory deficits even following right-sided surgery. No strong evidence of a material-specific, non-verbal memory deficit was found on commonly used tests of non-verbal memory. The majority of patients failed to show reliable decline in performance following surgery indicating that fears of post-operative memory decline may be unfounded.

Does liver dysfunction explain neuropsychological status in recently detoxified alcohol-dependent clients?

In the search for explanation of persistent cognitive impairment associated with alcohol dependence, the possible role of liver disease has aroused considerable interest. However, review of the relevant literature provides only ambiguous support for any general relationship between neuropsychological status and laboratory tests of liver function. We tested the general hypothesis, and also two specific hypotheses relating particular liver function parameters (gamma-glutamyl transferase and serum albumin) to mental ability in a sample of 54 recently detoxified alcohol-dependent people. Despite adequate design power, we failed to obtain evidence for general or specific correlations between mental ability and liver function. We conclude that the accumulated data do not provide direct support for the hypothesis that liver disease plays a part in the genesis of chronic alcohol-related brain impairment in clients without cirrhosis.

The hangover hypothesis and the influence of moderate social drinking on mental ability.

The "hangover" hypothesis proposes that there is some residual effect of low to moderate alcohol intake on the nervous system after the blood alcohol level has returned to zero. This notion has been invoked to explain the putative effects of moderate alcohol consumption on mental ability. We evaluated the hangover hypothesis by attempting to predict cognitive performance from self-reports of alcohol consumed during the week prior to testing. We found no meaningful evidence to support the notion that moderate alcohol ingestion produces a measurable toxic effect on brain function after the period of acute intoxication.